Mark Loewen is just the sort of guy you’d expect to bump into on the slopes of Mount Everest. In his youth, his love of canoeing and of the outdoors drew him to the pristine northern rivers of his home province, Manitoba, and to Canada’s Arctic. Later, an interest in mountain cultures and in recording and collecting folk music brought him to Pakistan and other parts of South Asia, where he established deep and enduring connections.

Along the way he picked up another vocation – science. “I always enjoyed science,” he says, “and excelled in chemistry.” Eventually, Loewen’s professional calling as an environmental chemist lured him back to South Asia and the flanks of Everest.

Mark Loewen is collaborating with researchers from other countries investigating the migration of pollution and its threat to public health. He has been studying the accumulation of toxic substances in sparsely populated places far from their industrial and agricultural sources – that is, in places where you would least expect to find them.

Toxic chemicals from on high

His Asian research follows up on earlier studies in Canada. Those studies detected elevated concentrations of toxic chemicals in the Arctic and in the “alpine” terrain around Banff, Alberta. “They were seeing fish with high levels of contaminants,” he explains. “How could that be? It’s not near any industrial source. There’s nothing pouring directly into the lakes. It turns out that those chemicals are ‘condensing’ in the mountains, and when the snow melts off, they flow down the rivers.”

These pesticides and heavy metals, in other words, behave much like ordinary H2O. In warm areas they evaporate and are transported on the wind. When they reach a cold area the poisonous substances “freeze out” and fall to Earth – and eventually find their way into the food chain.

The first phase of Loewen’s work in Asia focused on the Himalayas. The India-Nepal border has the practical advantage, from a research standpoint, of providing abrupt transitions from hot to cold. “The change in temperature happens over a very short distance. The Himalayas just come jumping out of the Gangetic Plains.”

His core discovery in this phase was that “a lot of the chemicals, although high in their ‘current use’ area in the Indian plains, are also high and peaking at about 5 000 metres above sea level – which just happens to be the average altitude of Tibet.” This finding inspired him to move north of the Himalayas during the IDRC-supported phase of his research.

On the ground research

The bulk of his current effort is devoted to measuring the contents of Tibetan air, in particular the pesticides and other agricultural compounds. Loewen and his team have deposited 11 passive air samplers on a path covering hundreds of kilometres of the Tibetan Plateau and nearby in Nepal. These simple, durable devices are left in place for a few months, then collected and returned to Canada – to the laboratory at Winnipeg's Freshwater Institute and to the Ultra-Clean Trace Elements Laboratory at the University of Manitoba – where their contents are analyzed to determine which chemicals are lurking in the atmosphere.

A practical concern for a study of this type is keeping the samplers protected and operating. One solution is to “hide” them in nooks and crannies. But even in such a relatively empty landscape as the Tibetan Plateau, Loewen says, “there are people roaming around everywhere.” His solution has been to engage with local people and to explain the importance of the research. “If people become interested in what you are doing, they’re more than happy to safeguard your sampler.”

Another of his research methods is to analyze the fallen snow and glacial melt. “Snow,” he points out, “is a good scavenger of chemicals.” Unlike paleo-climatologists who might take an 80-metre core sample to investigate the air the way it was millennia ago, his interest is in modern chemical invasions, and so he collects samples that represent just one or two years in order to assess seasonal deposition.

The link to food

Meanwhile, Mark Loewen has been collecting a third potential repository of toxins: butter. “For one thing, butter is an important part of Tibetans’ diet. But also, it is made of fat – and these toxins that we’re searching for happen to be fat soluble,” that is, they accumulate in fat. To ensure that the samples he takes away are locally produced, he seeks them from home-based production.

Thus his investigation addresses the entire path of the contaminant – from its source, through the air, then through the water, finally into the food. Much data gathering and analysis remains to be done, and Loewen is far from drawing definitive conclusions. But already he is worried about the significance of these issues, both for Tibetans and for the wider world.

“In Tibet, I don’t think people could get away without eating butter. It’s impossible to live up there without having a high fat diet. There’s nothing those people can do to shut off the tap of contamination. So you need to be thinking much more globally.”

A local and global concern

Nowadays Mark Loewen is based in south India, where his wife is doing HIV prevention research. From there he “commutes” to Nepal and Tibet. He realizes he is extremely lucky to be able to do research in such a politically sensitive region as Tibet. “Tibet is a beautiful place to work. It’s awe-inspiring.”

And what lies beyond the PhD? “We all need to get on board the Stockholm Convention on Persistent Organic Pollutants, and of course it’s best to do that locally. I’m working with Kathmandu University now to build an environmental lab. We aim to get people from all over the region – Tibetans, Chinese, Indians, Pakistanis – to meet there for training. It will be fantastic.”

But while he is acting locally, he is thinking globally. “Everybody in the world knows about Mount Everest. If people learn that there is contamination in such a remote and sacred place, maybe they will start putting pressure on their governments to act.”

Written by Patrick Kavanagh, an Ottawa-based writer and Senior English Writer and Communication Advisor for IDRC in Ottawa.